Although he's never tested it in a court of law, "Weird Al" Yankovic doesn't technically have to get permission from the artists he parodies. The 1994 Supreme Court case Campbell v. Acuff-Rose Music, Inc. established that parodies are protected by fair use laws, even if they make money for the creator of the parody. Still, "Weird Al" says he doesn't want to test any possible legal gray areas and doesn't want to anger anyone he's parodying, so he always makes sure they're cool with it before he goes ahead with a new song. They then share the money it generates.
Prince was the most famous person to consistently turn down Yankovic, rejecting his proposal to gently mock "When Doves Cry," "Let's Go Crazy," "Kiss" and many of his other hits. Paul McCartney was more open to the idea of a "Weird Al" parody, but he drew the line about 25 years ago when he was approached about a "Live and Let Die" take-off called "Chicken Pot Pie." Sample lyrics: "When we were young Bernie's Deli was down the block/He made great liver pâté/But if there's one thing in this world that I like better than a corn beef on rye/It's chicken pot pie."
"Paul didn't want me to do it because he's a strict vegetarian and he didn't want a parody that condoned the consumption of animal flesh," Yankovic recently told Conan O'Brien. "He said, 'You can do something else like tofu pot pie.' I said, 'No, the chorus of my song will be 'Bawk-bawk-bawk-bawk' and tofu doesn't make any noise. It's not going to work."
The complete rendition of "Chicken Pot Pie" never surfaced, but he did do a big chunk of it on a few 1990s tours as part of a medley. You can hear a recording of one right here. Just don't get inspired to eat an actual chicken pot pie because, you heard this: Paul McCartney wouldn't approve.